package com.ocean.doublepointer;

import java.util.Arrays;

/**
 * https://leetcode.cn/problems/reverse-string/
 * <p>
 * 反转字符串
 * <p>
 * 编写一个函数，其作用是将输入的字符串反转过来。输入字符串以字符数组 s 的形式给出。
 * <p>
 * 不要给另外的数组分配额外的空间，你必须原地修改输入数组、使用 O(1) 的额外空间解决这一问题。
 * <p>
 *  
 * <p>
 * 示例 1：
 * <p>
 * 输入：s = ["h","e","l","l","o"]
 * 输出：["o","l","l","e","h"]
 * 示例 2：
 * <p>
 * 输入：s = ["H","a","n","n","a","h"]
 * 输出：["h","a","n","n","a","H"]
 *  
 * <p>
 * 提示：
 * <p>
 * 1 <= s.length <= 105
 * s[i] 都是 ASCII 码表中的可打印字符
 *
 * @author linmiaolai@sanyygp.com<br>
 * @version 1.0<br>
 * @date 2023/03/27 <br>
 */
public class ReverseString {
    public static void main(String[] args) {
        ReverseString reverseString = new ReverseString();
        char[] s = {'h', 'e', 'l', 'l', 'o'};
        reverseString.reverseString(s);
        System.out.println(Arrays.toString(s));
        // s = ["H","a","n","n","a","h"]
        char[] t = {'H','a', 'n', 'n', 'a', 'h'};
        reverseString.reverseString(t);
        System.out.println(Arrays.toString(t));
    }

    public void reverseString(char[] s) {
        int n = s.length;
        int slow = 0;
        int fast = n - 1;
        while (slow < fast) {
            char pre = s[slow];
            s[slow] = s[fast];
            s[fast] = pre;
            slow++;
            fast--;
        }
    }
}
